LED headlights?

[der5997]

higssy: Rocky doesn't seem to have answered yet about the fibre optics and lenses.

Here's my take on what he may have meant.

Hold the end of a piece of plastic fibre optic material not far from a hot soldering iron. Watch what happens. That blob of plastic that forms makes the lens. You can cut off a stem for mounting the lens if all you're after is a replacement for a jewel. Or you can thread the fibre through the opening where the light would be, pull the lens into the light fitting, and arrange the free end against the light source inside the loco.

All this assumes that you drill out the back of the light fitting on the locomotive to receive the lens and fibre, or lens and stem. If you've ever searched the floor for a fallen jewel, you'll likely appreciate the extra handle a stem provides!

[der5997]

higssy: Rocky doesn't seem to have answered yet about the fibre optics and lenses.

Here's my take on what he may have meant.

Hold the end of a piece of plastic fibre optic material not far from a hot soldering iron. Watch what happens. That blob of plastic that forms makes the lens. You can cut off a stem for mounting the lens if all you're after is a replacement for a jewel. Or you can thread the fibre through the opening where the light would be, pull the lens into the light fitting, and arrange the free end against the light source inside the loco.

All this assumes that you drill out the back of the light fitting on the locomotive to receive the lens and fibre, or lens and stem. If you've ever searched the floor for a fallen jewel, you'll likely appreciate the extra handle a stem provides!

[Anonymous]

Thanks der5997, that's very informative. Should the fibre optics be available at the local hobby store or am I looking at Radio Shack or something like that?
The end your talking about at the light source, do you mean glued?

[Anonymous]

Thanks der5997, that's very informative. Should the fibre optics be available at the local hobby store or am I looking at Radio Shack or something like that?
The end your talking about at the light source, do you mean glued?

[Anonymous]

Fibre Optics: I use a lighter to heat the tip. It will form a convex "lense". I use .040" and .060". I pick the size that is slightly smaller than the opening and heat the fibre optic with the lighter until it is of diameter to seat in the opening. The soldering iron should work also.
1k (1,000-ohm) resistors: I read an article from Railroad Model Craftsman (sorry MR) "Demistifying DCC, Part 8". It covered how to use and care for LED's and bulbs. Works perfect with no problems. I have not lost an LED yet!
Jameco: The more you order, the cheaper it is. 1 led is 2.95 ea, 10 leds are 2.65 ea...shipping is reasonable. You can pick which method you want: FedEx, USPS, UPS, air, ground....I pick the cheapest.
I also use heat shrink to keep LED light out of the cab.

[Anonymous]

Fibre Optics: I use a lighter to heat the tip. It will form a convex "lense". I use .040" and .060". I pick the size that is slightly smaller than the opening and heat the fibre optic with the lighter until it is of diameter to seat in the opening. The soldering iron should work also.
1k (1,000-ohm) resistors: I read an article from Railroad Model Craftsman (sorry MR) "Demistifying DCC, Part 8". It covered how to use and care for LED's and bulbs. Works perfect with no problems. I have not lost an LED yet!
Jameco: The more you order, the cheaper it is. 1 led is 2.95 ea, 10 leds are 2.65 ea...shipping is reasonable. You can pick which method you want: FedEx, USPS, UPS, air, ground....I pick the cheapest.
I also use heat shrink to keep LED light out of the cab.

[Anonymous]

Answering the debate on whether or not the light output is AC or DC.
The output signal is varying from o volts to plus (insert 10-18 volts depending on P'supply input.)
It does not go below zero volts, therefore in one sense it is varying DC voltage, and will measure as DC on a DC input to your meter. However if you measure it on an AC meter, then the waveform looks roughly like a sine wave and will measure as AC.
However the reality is that it is DC, that is if you put a LED (or diode) across it, then one end of the Diode will always have positve jolts, while the other has negative jolts. Therefore care must be taken to get the polarity right.
Note that measurements obtained on either DC or AC meters are not accurate. The DC meter is only averaging what it sees., and the AC meter is cailbrated to read sine waves, not complex waves. For the purpose of calculating resistor values for 1.5v bulbs, the best bet is to build the little experimental resistor matrix that was a recent MR mag article.
Same arguement applies to pulse controllers, the output goes from zero to plus 12-16 volts with a variable pulse width determining the energy available to drive the DC motor. Throw the reverse switch and the output is still zero to 12-16 volts, but the zero changes from the left to right rail or vice versa. Again you can measure an inaccurate DC voltage or AC voltage.

[Anonymous]

Answering the debate on whether or not the light output is AC or DC.
The output signal is varying from o volts to plus (insert 10-18 volts depending on P'supply input.)
It does not go below zero volts, therefore in one sense it is varying DC voltage, and will measure as DC on a DC input to your meter. However if you measure it on an AC meter, then the waveform looks roughly like a sine wave and will measure as AC.
However the reality is that it is DC, that is if you put a LED (or diode) across it, then one end of the Diode will always have positve jolts, while the other has negative jolts. Therefore care must be taken to get the polarity right.
Note that measurements obtained on either DC or AC meters are not accurate. The DC meter is only averaging what it sees., and the AC meter is cailbrated to read sine waves, not complex waves. For the purpose of calculating resistor values for 1.5v bulbs, the best bet is to build the little experimental resistor matrix that was a recent MR mag article.
Same arguement applies to pulse controllers, the output goes from zero to plus 12-16 volts with a variable pulse width determining the energy available to drive the DC motor. Throw the reverse switch and the output is still zero to 12-16 volts, but the zero changes from the left to right rail or vice versa. Again you can measure an inaccurate DC voltage or AC voltage.

[cacole]

Try All Electronics (www.allelectronics.com) for LEDs of all shapes, sizes, and colors at surplus prices. For example, a white 3mm LED (Catalog Nr. LED-83) is priced at $2.85. Radio Shack probably doesn't even have this size LED in stock, and would want nearly $5 each if they did.

[cacole]

Try All Electronics (www.allelectronics.com) for LEDs of all shapes, sizes, and colors at surplus prices. For example, a white 3mm LED (Catalog Nr. LED-83) is priced at $2.85. Radio Shack probably doesn't even have this size LED in stock, and would want nearly $5 each if they did.

[der5997]

higssy: " Should the fibre optics be available at the local hobby store or am I looking at Radio Shack or something like that?" (haven't figured out how to quote in this Forum yet )

OK, your LHS should be able to get plastic fibre. However, there's a cheaper way to go. You know those table lamps that have fibre optics sprouting from them like a small bush? They were a fad some time ago. Fads end up in yard sales. Miles of very cheap fibre! Also, $ stores often sell party flashlights with a similar fibre "bush" on the end. Now, purists will say that these cheap fibres are not as light transmitting as the more pure expensive kinds. Doubtless they are right, but I wonder if you could tell the difference in the short run inside an N loco or caboose [;)]

Second point "The end your talking about at the light source, do you mean glued?"

Probably not glued to the bulb, because of heat considerations, and having to unglue to change a bulb.(the glue will degrade, and often discolour, which is not what you're after [:(]
However the wretched thing has to be fixed somewhere,or it will wander off and get out of alignment. So, glue or tape the fibre so that the end just butts up aganst the bulb or LED. A tiny gap is probably best for a bulb, again because of heat. With a LED you can go right against the thing.

[der5997]

higssy: " Should the fibre optics be available at the local hobby store or am I looking at Radio Shack or something like that?" (haven't figured out how to quote in this Forum yet )

OK, your LHS should be able to get plastic fibre. However, there's a cheaper way to go. You know those table lamps that have fibre optics sprouting from them like a small bush? They were a fad some time ago. Fads end up in yard sales. Miles of very cheap fibre! Also, $ stores often sell party flashlights with a similar fibre "bush" on the end. Now, purists will say that these cheap fibres are not as light transmitting as the more pure expensive kinds. Doubtless they are right, but I wonder if you could tell the difference in the short run inside an N loco or caboose [;)]

Second point "The end your talking about at the light source, do you mean glued?"

Probably not glued to the bulb, because of heat considerations, and having to unglue to change a bulb.(the glue will degrade, and often discolour, which is not what you're after [:(]
However the wretched thing has to be fixed somewhere,or it will wander off and get out of alignment. So, glue or tape the fibre so that the end just butts up aganst the bulb or LED. A tiny gap is probably best for a bulb, again because of heat. With a LED you can go right against the thing.

[der5997]

rocky451: Thanks for that heat shrink tip for keeping LED light out of the loco cab. ( I guess you don't use your lighter for shrinking that? [;)] )

[der5997]

rocky451: Thanks for that heat shrink tip for keeping LED light out of the loco cab. ( I guess you don't use your lighter for shrinking that? [;)] )

[Anonymous]

Fibre optic are in the Walthers catalog by several manufacturers. Not the cheapest way to buy, but they are available.
I do use my lighter to shrink the heat shrink tubing (carefully!).
I only use lighters for modeling and fireworks. I do not smoke.

[Anonymous]

Fibre optic are in the Walthers catalog by several manufacturers. Not the cheapest way to buy, but they are available.
I do use my lighter to shrink the heat shrink tubing (carefully!).
I only use lighters for modeling and fireworks. I do not smoke.

[Anonymous]

On my F-7s, I use some clear plastic tube to fill the headlight hole. I drilled holes to hold the lights. TRhe lights are in series with the motor. I polished the outer end using brass polish on demin. When the lights alternate, it looks like the Mars flasher. The cheap diodes 1n4001 have a 1.2v drop so if you parallel light the diode handles the current and pegs the light voltage. If you use a bridge you get directional lighting and it starts when you put more than 1and a half volts on the locomotive. I use a 20 watt light in the cabbose as a thyristor to protect lights. So you can use lights or LEDs. There are plenty of references to these diode ciircuits and they are simple. Lindsay

[Anonymous]

On my F-7s, I use some clear plastic tube to fill the headlight hole. I drilled holes to hold the lights. TRhe lights are in series with the motor. I polished the outer end using brass polish on demin. When the lights alternate, it looks like the Mars flasher. The cheap diodes 1n4001 have a 1.2v drop so if you parallel light the diode handles the current and pegs the light voltage. If you use a bridge you get directional lighting and it starts when you put more than 1and a half volts on the locomotive. I use a 20 watt light in the cabbose as a thyristor to protect lights. So you can use lights or LEDs. There are plenty of references to these diode ciircuits and they are simple. Lindsay

[Anonymous]

I attach fiber optics to lights with a dab of clear automotive silicon. It is easy to remove to change bulbs and doesn't discolor. Another source of cheap fiberoptic cable of high quality is used computer stores and your freindly neighborhood telephone man.

[Anonymous]

I attach fiber optics to lights with a dab of clear automotive silicon. It is easy to remove to change bulbs and doesn't discolor. Another source of cheap fiberoptic cable of high quality is used computer stores and your freindly neighborhood telephone man.

[Anonymous]

I've used LEDs I bought from eLED, eled.com, and had good success. Like B-dubya, I use a 1K ohm, 1/4 watt resistor for DCC applications. I have Digitrax and TCS decoders, and they've worked fine with my old Command 2000 and my new Prodigy control stations. I have not tested the ouput from the decoder to see if it's AC or DC, but I get good bright light. A little blue, but it looks ok to me.

Gary

[Anonymous]

I've used LEDs I bought from eLED, eled.com, and had good success. Like B-dubya, I use a 1K ohm, 1/4 watt resistor for DCC applications. I have Digitrax and TCS decoders, and they've worked fine with my old Command 2000 and my new Prodigy control stations. I have not tested the ouput from the decoder to see if it's AC or DC, but I get good bright light. A little blue, but it looks ok to me.

Gary

[der5997]

Wouldn't your friendly neighbourhood telephone man use glass fibre? If so, be careful handling the stuff in case it decides to take up residence in your skin [;)]
Also, with the glass fibre, does it melt easily to form a lens? I've not tried it, and am currious.

[der5997]

Wouldn't your friendly neighbourhood telephone man use glass fibre? If so, be careful handling the stuff in case it decides to take up residence in your skin [;)]
Also, with the glass fibre, does it melt easily to form a lens? I've not tried it, and am currious.

[Anonymous]

Have you tried white LED ditch lights. The only White LEDs I can find are large 5mm types. I was able to file them down to about 2mm (= 6.85 inches) and installed them in white metal frames (Details WEST?) under the anti clmber of a RPP SD90.
If you look at the electrodes within the LED , you can clearly see that they do not take up much space. I simply filed around the electrodes being careful not to file the face of the LED which becomes the lens.

[Anonymous]

Have you tried white LED ditch lights. The only White LEDs I can find are large 5mm types. I was able to file them down to about 2mm (= 6.85 inches) and installed them in white metal frames (Details WEST?) under the anti clmber of a RPP SD90.
If you look at the electrodes within the LED , you can clearly see that they do not take up much space. I simply filed around the electrodes being careful not to file the face of the LED which becomes the lens.

[Anonymous]

QUOTE: Originally posted by der5997

Wouldn't your friendly neighbourhood telephone man use glass fibre? If so, be careful handling the stuff in case it decides to take up residence in your skin [;)]
Also, with the glass fibre, does it melt easily to form a lens? I've not tried it, and am currious.

It takes a very high temperature to melt glass, a gas burner or electric arc. Also the light carrying core of glass fiber is very small, 10 micron diameter in telephone singlemode fiber; 62.5 micron in LAN multimode fiber, which to your eyes would look like a pinpoint. The entire fiber diameter if you did form a lens is 125 micron, thin as a hair. The fiber is too small to efficiently couple light into it. Large core plastic fiber is better for model RR use.

You are right about getting it into your skin. Ouch!

[Anonymous]

QUOTE: Originally posted by der5997

Wouldn't your friendly neighbourhood telephone man use glass fibre? If so, be careful handling the stuff in case it decides to take up residence in your skin [;)]
Also, with the glass fibre, does it melt easily to form a lens? I've not tried it, and am currious.

It takes a very high temperature to melt glass, a gas burner or electric arc. Also the light carrying core of glass fiber is very small, 10 micron diameter in telephone singlemode fiber; 62.5 micron in LAN multimode fiber, which to your eyes would look like a pinpoint. The entire fiber diameter if you did form a lens is 125 micron, thin as a hair. The fiber is too small to efficiently couple light into it. Large core plastic fiber is better for model RR use.

You are right about getting it into your skin. Ouch!

[der5997]

JohnDM: Thanks for t he filing down info. that was going to be my next question. I had read that te white LED is in fact 3 separate LEDs in one package all firing at the same tiem and mixing their light to white. So, I thoufght, that must mean a bigger package. Apparently not, and thanks again for the info.

[der5997]

JohnDM: Thanks for t he filing down info. that was going to be my next question. I had read that te white LED is in fact 3 separate LEDs in one package all firing at the same tiem and mixing their light to white. So, I thoufght, that must mean a bigger package. Apparently not, and thanks again for the info.